Experimental Study on Thermal Conductivity of Cement and Lime Improved Loess

Abstract

Based on the stable plate method principle, a set of testing devices to test the thermal conductivity coefficient of unsaturated porous media materials were developed. For these testing devices, the testing process of the devices is closer to the real conduction process of the material, the testing results have sufficient accuracy for engineering application,and with the advantages of simple principle and convenient operation , it has a certain reference value in the practical application. On the basis of the experimental study on thermal conductivity coefficient of loess and two kinds of improved loess by these devices, relation curves between thermal conductivity coefficient and dry density, as well as the impact of cement improvement and lime improvement on the thermal conductivity, were obtained. The results show that the thermal conductivity coefficient of loess increased with the dry density; and reduced after being improved by cement, but the reduction is not obvious; After being improved by lime the thermal conductivity coefficient of loess was significantly increased, but the increasing rate of the thermal conductivity coefficient decreased gradually with the lime content increasing, and when the lime content reaches a critical value, the thermal conductivity coefficient will decrease with it.